We assessed the performance of ten incidence-based estimators of tree species richness in simulated simple random sampling with fixed-area plots. Stem diameter-limited tree species and location data came from two species-rich wet tropical forest compartments in Panama and India. Lower
limits of stem diameter were 1 cm and 30 cm, respectively. Estimators varied widely in their estimates of richness and their rankings changed frequently across sites and sample designs. A gamma-Poisson estimator was overall best according to a performance score of three accuracy statistics
and sample size. However, until corroborated by further studies, Chao's 1981 non-parametric estimator is recommended for forest inventories with fixed-area plots.

The International Forestry Review is a peer-reviewed scholarly journal that publishes original research and review papers on all aspects of forest policy and science, with an emphasis on issues of transnational significance. It is published four times per year, in March, June, September and December. Theme editions are a regular feature and attract a wide audience.